JPH06332036A - Clamping structure of light-shielding blade - Google Patents

Abstract

(57) [Summary] [Purpose] Achieving simple and stable quality, which does not depend on the material of the blade, and does not require skill of caulking work, and yet has high caulking strength. [Structure] A caulking pin having a cylindrical portion and a cylindrical caulking foot portion having a diameter smaller than that of the cylindrical portion, a connecting member through which the cylindrical portion is inserted, and a light-shielding blade through which the caulking foot portion is inserted are added. In the structure that is connected by tightening, the stepped surface caused by the difference in diameter between the columnar portion and the caulking foot is formed into a flat surface parallel to the lower surface of the head of the caulking pin, and the caulking foot is expanded and bent. The light-shielding blade is sandwiched between the step and the step surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light shielding blade crimping structure for crimping a caulking pin to a light shielding blade used for a shutter or an aperture of a camera.

[0002]

2. Description of the Related Art In recent years, there has been a demand for higher camera shutter speeds and strobe synchronization speeds for reasons such as improvement in film sensitivity and desire for new image expression.
A camera that realizes a high shutter speed of 0 second and a flash synchronization speed of 1/250 second is provided.

A conventional focal plane shutter has a main arm and a slave arm which are rotatably connected to a shutter base plate and a plurality of divided blades by caulking pins to form a parallel link. A drive pin that engages with a drive pin hole formed in the main arm causes each of the split blades to be expanded from the folded state outside the exposure window of the shutter substrate to the expanded state so as to cover the exposure window. It is configured to move from the folded state to the folded state.

Conventional crimping in which a blade is rotatably connected to an arm by a crimping pin will be described with reference to FIG.

The light-shielding blade 2 is embossed in advance by press molding so as to have a recess 2a.
The arm 1 and the light-shielding blade 2 are connected by pushing and expanding the caulking foot portion 3a with the caulking foot portion 3a of the caulking pin 3 being inserted into the caulking pin insertion hole 2b of the light shielding blade 2. I am letting you.

[0006]

However, since the light-shielding blade 2 is embossed, when the light-shielding blade 2 is made of metal, cracks occur, the embossed shape varies, and the flatness of the light-shielding blade 2 deteriorates. However, there is a problem in that the quality is varied, such as the tightening strength being weakened.

Further, when the light-shielding blade 2 is made of plastic, there is a problem that the embossed shape cannot be made well due to the resilience of the plastic material, and improvement has been demanded.

Japanese Unexamined Patent Publication (Kokai) No. 62-47628 discloses a crimping method effective for a material such as a fiber reinforced composite material which cannot be embossed. If the strength of the reinforced composite material varies, there is a problem that the flatness is deteriorated and the caulking strength is lowered. Therefore, an improved caulking method is still demanded.

Also, the shutter speed is 1/8000 seconds,
There is a demand for an ultra-high speed shutter that exceeds the flash synchronization speed of 1/250 seconds. To enable this,
Among fiber reinforced composite materials, there is a desire to use a material having higher rigidity. However, in the conventional method, since the material is highly rigid, the vicinity of the crimped portion becomes a considerably large concave shape. Therefore, there is a problem that the interference between the blades is increased and the running resistance is increased, and that the flatness is greatly deteriorated. Furthermore, if the light-shielding blades are crimped without embossing, the foot of the crimping pin protrudes from the blades, which adversely affects the high-speed running.

The present invention has been made in view of the above problems, and is simple and stable in quality without depending on the material of the blade, and without requiring skill of caulking work, and yet has a caulking strength. The purpose is to achieve high crimping.

[0011]

In order to achieve this object, a method of crimping a light-shielding blade according to the present invention comprises a cylindrical portion (3
d) and a cylindrical caulking foot portion (3a) having a diameter smaller than that of the cylindrical portion.
The caulking pin (3) having the above, the coupling member (1) through which the columnar portion (3d) is inserted, and the light shielding blade (2) through which the caulking foot portion (3a) is inserted are caulked and coupled. In structure,
The step surface (3c) caused by the difference in diameter between the columnar portion (3d) and the caulking foot portion (3a) is used as a lower surface (3e) of the head of the caulking pin (3).
The light shielding blade (2) is sandwiched between the caulking foot portion (3a) and the stepped surface (3c) which are formed in a plane shape parallel to and are pressed and expanded.

[0012]

In the crimping structure of the light-shielding blade having the above-described structure, the light-shielding blade is sandwiched between the flat stepped surface and the crimping leg portion which is expanded and bent. It can be caulked as it is and connected to the connecting member. As a result, it is possible to realize the crimping which is simple and stable in quality, and which has high crimping strength, without depending on the material of the blade and without requiring skill of crimping work.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial sectional view showing an embodiment of a method for crimping a light-shielding blade according to the present invention, showing a state before crimping of a crimp portion.

In FIG. 1, 1 is an arm, 2 is a light-shielding blade, and 3 is a caulking pin. The caulking pin 3 has a cylindrical portion 3d.
And a cylindrical caulking foot portion 3a having a diameter smaller than that of the cylindrical portion 3d. The step surface 3c caused by the difference in diameter between the cylindrical portion 3d and the caulking foot portion 3a is formed in a plane shape parallel to the head lower surface 3e of the caulking pin 3. The caulking pin 3 is inserted into the caulking pin insertion hole 1a of the arm 1 at the cylindrical portion 3d, and is inserted into the caulking pin insertion hole 2b of the light shielding blade 2 at the caulking leg portion 3a.

The caulking foot portion 3a of the caulking pin 3 is formed into a cylindrical shape, and the corner portion inside the cylinder is formed into an inclined surface with respect to the cylindrical surface like the chamfered portion 3b.
The step surface 3c of the caulking pin 3 is formed perpendicular to the cylindrical surface of the caulking foot portion 3a.

Next, the caulking work will be described. First, the caulking pin 3 is inserted into the caulking pin insertion hole 1a of the arm 1.
Next, the caulking leg portion 3a of the caulking pin 3 is inserted into the caulking pin insertion hole 2b of the light shielding blade 2, and the head of the caulking pin 3 is held by a mold (not shown). In this state, caulking pin 3
When the punch 4 is moved in the direction of the arrow from below,
a is bent outward. The peripheral portion of the caulking pin insertion hole 2b of the light shielding blade 2 is pressed against the step surface 3c and is sandwiched between the bent caulking leg portion 3a and the step surface 3c. At this time, the planar shape of the light-shielding blade 2 is maintained including the portion sandwiched between the caulking foot portion 3a and the step surface 3c. This state is shown in FIG.

As described above, the planar light-shielding blade 2 is firmly clamped between the step surface 3c and the bent caulking leg portion 3a while being planar. Here chamfer 3b
Is formed, the caulking foot portion 3 after being bent
Although a protrudes from the light-shielding blade 2, that portion has a substantially flat or gentle curved surface shape. Therefore, even if another shading blade runs adjacent to the shading blade 2,
It is adapted to ride on the crimped foot portion 3a without colliding with the bent crimped foot portion 3a.

Further, the caulking strength is about 0.1 kg · cm when measured with a torque wrench or the like in the conventional method, and variations in the strength have occurred, but according to the present invention, the strength or the strength is more than double. The strength until the material was broken was stably obtained. Furthermore, when the caulking pin 3 whose inner surface of the caulking foot 3a is chamfered is used, the tip of the caulking foot 3a is thin when the caulking foot 3a is expanded by a punch or the like. , Without using special skilled work, using special tools, using special materials for light-shielding blades, or performing special processing,
The tip of the caulking foot portion 3a curls and comes into close contact with the light shielding blade 2.

For this reason, the caulking foot portion 3a protrudes from the light-shielding blade 2, but since the caulking foot portion 3a is almost flat or has a gentle convex shape, the caulking foot portion 3a rides up well even if another light-shielding blade 2 overlaps, and the tip of the caulking foot portion 3a is located. There is almost no accident caused by being caught on the light-shielding blade 2 and scratches due to the caulking foot portion 3a, which has been a problem in the past. It was also found that the running resistance hardly increased because the contact area was small.

Furthermore, the crimping method of the present invention can be used by replacing it with the conventional crimping method, and the cost can be reduced because the process can be simplified and the quality can be stabilized. Become. Also, since the caulking strength is dramatically improved as compared with the conventional method, the shutter speed is 1/8000 seconds,
The flash speed can be increased to over 1/250 seconds and the durability can be significantly improved.

As described in detail above, according to the present invention, since the light-shielding blades can be caulked and connected in a flat state, it is possible to emboss not only metal or plastic but also fiber-reinforced composite material. Regardless of the material of the blades, including the materials that cannot be applied, it is possible to easily perform stable caulking with high caulking strength without requiring skill in caulking work.

Further, since the blades are not deformed, there is no fear of deterioration of the flatness of the blades, and caulking work with a high yield rate can be realized. In addition, the caulking work could not be done until now,
It is possible to use a material that could not be used for the light-shielding blade for the ultra-high-speed shutter due to insufficient tightening strength, and it is possible to further reduce the weight and speed.

[0024]

As described above, according to the method for crimping the light-shielding blade of the present invention, the light-shielding blade is sandwiched between the flat stepped surface and the crimped leg portion which is spread and bent. Therefore, the light shielding blade can be crimped and connected to the connecting member in a flat state. As a result, it is possible to realize the crimping which is simple and stable in quality, and which has high crimping strength, without depending on the material of the blade and without requiring skill of crimping work.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of a method for crimping a light shielding blade according to the present invention.

FIG. 2 is a partial cross-sectional view showing an embodiment of a method for crimping a light-shielding blade according to the present invention.

FIG. 3 is a partial cross-sectional view showing an example of a conventional method of crimping a light shielding blade.

[Explanation of symbols]

 1 arm 1a caulking pin insertion hole 2 light-shielding blade 2a recess 2b caulking pin insertion hole 3 caulking pin 3a caulking foot 3b chamfer 3c stepped surface 3d columnar portion 3e head lower surface

Claims (2)

[Claims] 1. A caulking pin having a cylindrical portion and a cylindrical caulking foot portion having a diameter smaller than that of the cylindrical portion, a connecting member through which the cylindrical portion is inserted, and the caulking foot portion is inserted. In a structure in which a light-shielding blade is connected by caulking, a step surface caused by a difference in diameter between the columnar portion and the caulking foot portion is formed in a plane shape parallel to the lower surface of the head of the caulking pin,
A crimping structure for a light-shielding blade, wherein the light-shielding blade is sandwiched between the crimping foot portion that is spread and bent and the step surface. 2. The caulking structure for a light-shielding blade according to claim 1, wherein the inside of the head of the cylindrical caulking foot portion is chamfered.